Stoker driving mechanism.



M. ALPERN. STOKER DRIVING MECHANISM.

APPLICATION FILED OCT. 2} 1 914.

Patented J uly 9,1918,

3 SHEETSSHEET I.

g9 hag-E501 I l I r M. ALPERN.

STOKER DRIVING MECHANISM.

' APPLICATION FILED II'I'cT. 2, I914. 1,271,649. Patented July 9,1918.

3 SHEETSSHEET 2.

l lHlll I 7 III! R M. ALPERN. STOKER DRIVING MECHANISM. APPLICATION FILED OCT. 25191-4.

E Z w 7D Z I P n F I m m I Z MAXWELL ALPERN, OF PHILADELPHIA, PENNSYLVANIA, ASSIGNOR TO AMERICAN I ENGINEERING COMPANY, OF PHILADELPHIA,1.PENNSYLVANIA, A CORPORATION OF PENNSYLVANIA.

" STOKER DRIVING MECHANISM.

Patented July 9, 1918.

Application filed October 2, 1914. Serial No. 864,620.

To all whom it may concern:

Be it known that I, MAXWELL ALPnRN, a citizen of the United States, residing in Philadelphia, Pennsylvania, have invented certain Improvements in Stoker Driving ,Mechanism, of which the following is a specification. p One object of my invention is to provrde a novel combination of parts for transmitting power from a suitable source to the pushers or other fuel feeding devices of an automatic stoker, which shall be characterized by its freedom from gearing, low speed, economical use of power and the ease with which it may be assembled and maintained inworking order.

I further desire to provide a Stoker driving mechanism in which each retort shall be provided with an independently driven fuel feeding device, so designed that it may be stopped or started without affecting the similar mechanism of any other retort and the intention also contemplates a relatively simple and conveniently operative means for controlling the operation of each dIlVlIlg unit. r

I also desire to provide a mechanism of the class indicated in which all the pushers of the several retorts shall receive power through independently driven vertical yshafts, so mounted as to facilitate the assembly of the apparatus, the whole mechanism being of such a nature as not torequire accurate alining of the main driving shaft relatively to the pushers or their associated mechanism.

Another object of my invention is to provide a novel and relatively simple safety device whereby the driving apparatus of any retort shall be automatically disconnected from the driving shaft whenever any abnormal obstruction prevents proper opera tion of its pusher or plunger, the arrangement of partsbeing such that a broken device may be conveniently renewed and the parts again placed in operation after the obstruction has been removed.

These objects and other advantageous ends I secure as hereinafter set forth, reference being had to the which Figure 1 is a plan of the feeding mecha- 'nism for three retorts of a stoker arranged in accordance with my invention;

accompanying drawings in Fig. 2 is a rear elevation of the mechanism shown in Fig. 1;

Fig, 3 is a. vertical aa, F ig. 2;

Figs. 4, 5, and 6 are respectively a rear elevation, a plan, and a side elevation of a modified form of safety device.

In the'above drawings 1 represents the front portion of a stoker structure having a number of retorts of which the rear part of one is illustrated at 2 as connecting with the front end of a cylindrical chamber or cylinder 3 containing. a reciprocable pusher or plunger 4. In the present instance I have shown three cylinders supplied with fuel from hoppers 5 5", and 5, respectively, each of which opens into the top of the forward portion of its cylinder. Each ofthe pushers 4 has pivoted to it a rearwardly extending connecting rod 6, driven through a crankpin 7 by a crank-arm 8, fixed in any suitable manner to a vertical shaft 9.. These latter are each mounted ina pair of bearings 10 and 11, carried by a casting 12, suit-ably supsection on the line ported from a plate-like projection formed integral with the rear end of the adjacent cylinder 3.

Fixed to each of the shafts 9, between the bearings 10 and 11, is a ratchet wheel 14 and this is acted-on by a pawl 15, pivotally mounted between a pair of rigidly connected arms 16 and17, rotatably mounted on said shaft 9 on opposite sides of the wheel 14.

The arm 17 has its forward end extended and pivotally connected by a bolt 18 to a constantly reciprocated main driving shaft 19, carried in bearings 20. fixed to the rear 1 face of the stoker structure 1.

Each of the pawls is normally pressed to- -ward the teeth of its ratchet wheel 14 by a spring 21 and is connected through a detachable hook 22, to a controlling handle 23 pivoted to the rear end of the arm 17. This sition in which it is inline with the hook 22. The toggle necessarily remains in this condition until moved by hand through its straight position and while the pawl is thus disengaged the pusher with which it is associated is operatively disconnected from the driving shaft.

The crank-pin ,7 is operatively attached to the connecting rod 6 by a safety-pin 24, and for this purpose its upper end is formed to slidably receive the end of said rod 6. This latter, as Well as the crank-pin, has mounted in it alined steel bushings 25 and 26, through which the pin 21 passes,vit being noted that this latter is composed of some material, such as hard brittle steel, which when subjected to suflic-ient shearing stress will break with a clean sharp fracture.

Under conditions of operation the driving shaft 19 is reciprocated from a suitable source of power at a relatively low speed, it being noted that its supporting bearings 20 are carried on the main structure frame and may easily be alined. Fuel is supplied 'to the mittently fed into the retorts 2 by the reciprocating action of the pushers 4. These are intermittently moved by power transmitted from the shaft 19 to the arms 17 and 7 from each'of these through its pawl 15 to the cooperating ratchet wheel ll, the vertical shaft 9, crank 8, crank-pin 7, and connecting rod 6. Obviously if some hard body, such as a mass of iron, be engaged by one of the thereby withdrawing said pusher to its extreme outer position, in which it would. remain undisturbed wlthout affecting the operation of the other pushers of the stoker. hen it is desired to replace the broken safety-pi Phe handle 23 of that particular unit is moved outwardly to withdraw the pawl from engagement with the ratchet wheel and leave the arm 17 free to be oscillated by the main shaft 19. After the fragments of the pin have been removed from the bushings 25 and 26 of the crank-pin and connecting rod, these latter are again brought into alinement and a new pin is insorted. i

, If at any time the fire in the furnace supplied by the stoker is burning unevenly, one or more of the pushers 4 feeding retorts in which there is an excess of fuel may be thrown out of operation by disengaging the corresponding pawl or pawls 15, thereby permitting the furnace to operate without gage the head 6 operated with the expenditure of materially less power than has heretofore been considered possible .or practical, since in place of a rotary drivmg shaft operating at a relatively high speed, I have employed alongitudinal reciprocating shaft operating at a relatively low speed, depending upon the proportions of the parts. Not only does the use of the vertical shafts 9 materially facilitate in the assembly of the parts, but as shown particularly in Fig. 3, it increases the accessibility and simplification of the mechanism. various hoppers 5 5 and 5 and 1s mterv In the modified form of safety device shown in Figs. 4, 5, and 6, the crank-pin 7 a is provided with a head 30, having a hori-.

zontal passage for the reception of the end of the connecting rod 6. In this case said rod is formed with a spherically curved head 6 and the head of the crank-pin has two oppositely projecting lugs 31 to each of which is pivoted or hinged a swinging arm 32. The ends of these latter approach to within a short distance of each other and are preferably recessed so as to closely engage the head 6 of the, connecting rod 6, being separably connected by a comparatively weak tension pin or link 33. This latter is headed at each end and lies within upwardly opening recesses formed in the extremities of the arms 32, so as to be easily inserted or removed. As shown, said pin tapers from its ends to its central portion which for a short distance lies within the open space between the opposed ends of the swinging arms 32.

Under conditions of normal operation the connecting rod and with it the pusher l, is alternately moved toward and from the retort, as the crank 8 with the pin 7 is rotated by the shaft 9. In the event, however, of any abnormal opposition being offered to the movement of the connecting rod, such as might be caused by the presence of a body of metal in the bottom of the hopper 5, the pressure exerted by the crank-pin upon said rod would be such as to increase the tension on the safety-pin 33 to the breaking point, whereupon the arms 32 would swing apart and-permit the head 30 of the crank pin to slide inwardly on the rod 6. As in that form of my invention shown in Fig. 3, the continued rotation of the crank would there-,

after cause the head of the crank pin to enof the connecting rod with the result that the pusher 4' would be drawn outwardly to the outer end of the cylinder or chamber 3, Where-it would remain until the obstruction was removed and the arms 32 were again operatively connected by a new.

ments; a reciprocating driving shaft movable in a line at right angles to the lines of movement of said elements; and means including a pawl and a ratchet for independently connecting each of. said elements with the driving shaft, the pawls being operated by said shaft.

3. The combination in astoker feeding device of a reciprocating element operative in a substantially horizontal line; a vertically mounted shaft; an overhung crank on the shaft connected to said element; and a longitudinally reciprocating driving shaft connected to intermittently rotate said vertical shaft.

4. The combination in a stoker feeding mechanism of a series of reciprogating elements operative in substantially horizontal lines; verticaloperating shafts respectively connected to said elements; a substantially horizontal longitudinally reciprocating driving shaft; and means for operatively connecting each of said vertical shafts with said driving shaft.

, 5. The combinatlon in a stoker feeding mechanismlof a series of reciprocating elements operative in substantially horizontal lines; vertical operating shafts respectivelyconnected to said elements; a substantially horizontal longitudinally reciprocating driving shaft; and means for operatively connecting each of said vertical shafts with said driving shaft; the same consisting of an oscillatory arm connected to the driving shaft; a ratchet wheel connected to the 'vertical shaft; and a pawl carried by said arm in position to co-act with the ratchet wheel, v 6. The combination in a stoker feeding mechanism of a reciprocating element; a a

rotatable shaft extended at right angles to the line of 'movement of said element; a crank and a ratchet Wheel fixed to said shaft so as to rotate in horizontal planes; a bar connecting said crank with the element; a reciprocating driving shaft extending in a line at right angles to said first shaft; with a pawl actuated by the driving shaft and operative on the ratchet wheel.

7. The combination in a stoker feeding mechanism of a reciprocating pusher; a con necting rod attached thereto; a crank having a pin through which said rod is longitudinally slidable under certain abnormal conditions; means for driving said crank; and a structurally weak element operatively cggnecting the crank pin and the connecting r 8. The combination in a stoker feeding mechanism of a reciprocating element; a

rotary shaft mounted in a line at right angles to the line of movement of said element; a crank driven from said shaft and having a crank-pin; aheaded connecting rod attached to the element and slidable through said crank-pin; a structurally weak pinoperatively connecting the crank-pin and the connecting rod; with bushings respectively mounted in the crank-pin and in the con necting rod, in which said structurally weak pin is mounted.

,9, The combination in stoker feeding mechanism of a reciprocating pusher; an overhung crank; a rod connected to the pusher and formed to be capable of longitudinally sliding through said crank under certain abnormal conditions; a-structurally weak member connecting the rod and said crank to normally prevent sliding of said rod through the latter; and means for driving the crank.

10. A stoker feeding mechanism comprising a series of reciprocating pushers opera tive in substantially horizontal lines, a series of independent vertical shafts, means for operating said shafts in the same direction,

over-hung cranks on the upper ends of the shafts, and means connecting said cranks with said pushers.

In testimony whereof, I have signed my name to this specification, in the presence of two subscribing witnesses. 7/

MAXWELL ALPERN. Witnesses: I

C. L. SMITH, M. EMMA Bnnonss. 

